Quail (Coturnix japonica) egg attenuated 2-butoxyethanol-induced enzymatic dysregulation, disseminated thrombosis and hemolytic impairment in female wistar rats.

Influence of quail egg on pathologies has increased research interests and series of investigations are currently being done on its influence against these pathologies. The influence of quail egg against 2-butoxyethanol induced hemolysis and disseminated thrombosis was investigated to determine the enzymatic regulations that ensue in the amelioration of deleterious hemolytic and disseminated thrombosis displayed in female Wistar rats. Quail egg was separated into three (3) components (extracts)-quail egg yolk water soluble (QYWS) and fat soluble (QYFS), and albumen extract (QA) and the inorganic and organic compositions were characterized. Depranocytotic assaults was achieved by 250 mg/kg of 2-Butoxyethanol administered for 4 days, the clinical observation revealed a dark purple-red discoloration on the distal tails of the rats and therapeutic applications followed with 1000 mg/kg BWT of QYWS, QYFS and QA, and 15 mg/kg BWT of hydroxyurea. Morphological evaluation, haematological estimations and biochemical evaluations of the influence on the activities of sphingosine kinase-1, RNase, red cell carbonic anhydrase, lactate dehydrogenase, glutathione peroxidase and caspase-3, vis a vis the concentrations of sphingosine-1 phosphate, selenium and zinc (plasma and urine). In vitro anti-inflammatory influence of quail egg components were investigated against hemolysis and key enzymes of inflammation-cycloxygenase, lipoxygenase and ß-glucuronidase. The in vitro anti-inflammatory effects of QYWS, QYFS and QA were concentration dependent from 200 to 800 µg/ml against hemolysis and the key enzymes of inflammation. The characterization of inorganic and organic bioactive composition of the yolk and albumen revealed the presence of folic acid, cobalamin, pyridine, riboflavin, ascorbic acid as well as vitamins D and E, selenium, zinc, iron and calcium. These had reflected in the attenuation of the induced hemolytic and disseminated thrombosis by regulations of enzymes linked to the infarction, apoptosis and oxidative stress characterized in sickle cell index.

VZHE-039, a novel antisickling agent that prevents erythrocyte sickling under both hypoxic and anoxic conditions.

Sickle cell disease (SCD) results from a hemoglobin (Hb) mutation ßGlu6 → ßVal6 that changes normal Hb (HbA) into sickle Hb (HbS). Under hypoxia, HbS polymerizes into rigid fibers, causing red blood cells (RBCs) to sickle; leading to numerous adverse pathological effects. The RBC sickling is made worse by the low oxygen (O2) affinity of HbS, due to elevated intra-RBC concentrations of the natural Hb effector, 2,3-diphosphoglycerate. This has prompted the development of Hb modifiers, such as aromatic aldehydes, with the intent of increasing Hb affinity for O2 with subsequent prevention of RBC sickling. One such molecule, Voxelotor was recently approved by U.S. FDA to treat SCD. Here we report results of a novel aromatic aldehyde, VZHE-039, that mimics both the O2-dependent and O2-independent antisickling properties of fetal hemoglobin. The latter mechanism of action-as elucidated through crystallographic and biological studies-is likely due to disruption of key intermolecular contacts necessary for stable HbS polymer formation. This dual antisickling mechanism, in addition to VZHE-039 metabolic stability, has translated into significantly enhanced and sustained pharmacologic activities. Finally, VZHE-039 showed no significant inhibition of several CYPs, demonstrated efficient RBC partitioning and high membrane permeability, and is not an efflux transporter (P-gp) substrate.

In vitro assessment of the anti-sickling properties of Buchholzia coriacea and Mucuna pruriens seed extracts.

Sickle cell disease is a group of diseases inherited through the gene and it affects the haemoglobin in the red blood cell. This study investigated the methanol seed extract of Buchholzia coriacea for possible in vitro anti-sickling effects and also determined the effect of Mucuna pruriens seed extract on the solubility and oxygen-binding rate of sickle cell haemoglobin. Sickle cell blood was collected from sickle cell disease patients with subsequent addition of 2% sodium metabisulphite to cause more sickling. Varying concentrations of the seed extracts (50%, 25%, 12.5% and 6.25%) were added to the pre-treated blood for these in vitro assays. The results showed that the extract of Buchholzia coriacea significantly (P < 0.05) inhibited sickling at all concentrations with the highest percentage inhibition of 73.3 ± 5.8, reversed sickled erythrocytes at all concentrations with the highest percentage reversal of 83.3 ± 5.8 and significantly (P < 0.05) inhibited polymerisation at all concentrations used in comparison to the parallel control. The extract of Mucuna pruriens seed significantly (P < 0.05) increased the solubility of sickle haemoglobin at 50%, 25%, 12.5% and 6.25% concentrations, increased Fe2+/Fe3+ ratio from 1.7 (control) to 12.2 (50% concentration) and reduced osmotic fragility (at 12.5% and 6.25% concentrations) when compared with parallel control. The results indicate the feasibility of the seed extracts as promising agents in the management of sickle cell disease.

Adaptation of a microbead assay for the easy evaluation of traditional anti-sickling medicines: application to DREPANOSTAT and FACA.

CONTEXT: Sickle cell disease is a common inherited blood disorder affecting millions of people worldwide. Due to lack of progress in drug discovery for a suitable treatment, sufferers often turn to traditional medicines that take advantage of the plant extracts activity used by traditional healers. OBJECTIVE: This study optimizes an anti-sickling screening test to identify preparations capable of reverting sickle cells back to the morphology of normal red blood cells. We focused on the miniaturization and practicability of the assay, so that it can be adapted to the laboratory conditions commonly found in less developed countries. MATERIALS AND METHODS: We tested two traditional anti-sickling herbal medicines, FACA® and DREPANOSTAT®, composed of Zanthoxylum zanthoxyloides (Lam.) Zepern. & Timler (Rutaceae) and Calotropis procera (Aiton) Dryand. (Apocynaceae) at screening concentrations of hydroethanol extracts from 0.2 to 1 mg/mL. Potential bioactive molecules present in the extracts were profiled using Ultra High Performance Liquid Chromatography coupled with High Resolution Mass Spectrometry (UHPLC-HRMS/MS) method, identified through HRMS, MS/MS spectra and in silico fragmentation tools. RESULTS: Hydroethanol extracts of FACA® and DREPANOSTAT® showed low anti-sickling activity, inhibiting less than 10% of the sickling process. The UHPLC-HRMS/MS profiles identified 28 compounds (18 in FACA® and 15 in DREPANOSTAT®, including common compounds) among which l-phenylalanine is already described as potential anti-sickling agent. When used as positive control, 7 mg/mL phenylalanine reduced the sickled RBC to 52%. DISCUSSION AND CONCLUSIONS: This assay has been optimized for the easy screening of plant extracts or extracted compounds from bioassay guided fractionation, valuable to laboratories from less developed countries.

Potential of Three Ethnomedicinal Plants as Antisickling Agents.

Sickle cell disease (SCD) is a genetic blood disorder that affects the shape and transportation of red blood cells (RBCs) in blood vessels, leading to various clinical complications. Many drugs that are available for treating the disease are insufficiently effective, toxic, or too expensive. Therefore, there is a pressing need for safe, effective, and inexpensive therapeutic agents from indigenous plants used in ethnomedicines. The potential of aqueous extracts of Cajanus cajan leaf and seed, Zanthoxylum zanthoxyloides leaf, and Carica papaya leaf in sickle cell disease management was investigated in vitro using freshly prepared 2% sodium metabisulfite for sickling induction. The results indicated that the percentage of sickled cells, which was initially 91.6% in the control, was reduced to 29.3%, 41.7%, 32.8%, 38.2%, 47.6%, in the presence of hydroxyurea, C. cajan seed, C. cajan leaf, Z. zanthoxyloides leaf, and C. papaya leaf extracts, respectively, where the rate of polymerization inhibition was 6.5, 5.9, 8.0, 6.6, and 6.0 (×10-2) accordingly. It was also found that the RBC resistance to hemolysis was increased in the presence of the tested agents as indicated by the reduction of the percentage of hemolyzed cells from 100% to 0%. The phytochemical screening results indicated the presence of important phytochemicals including tannins, saponins, alkaloids, flavonoids, and glycosides in all the plant extracts. Finally, gas chromatography-mass spectrometry analysis showed the presence of important secondary metabolites in the plants. These results suggest that the plant extracts have some potential to be used as alternative antisickling therapy to hydroxyurea in SCD management.

Biological activity of liposomal vanillin.

This article presents a study of vanillin encapsulation inside multilamellar liposomes, with emphasis on the evaluation of antioxidant activity, the hemolytic effect, and the antisickling properties of these products. Egg phosphatidylcholine-cholesterol and egg phosphatidylcholine-cholesterol-1-O-decylglycerol liposomes were prepared by mechanical dispersion, all with vanillin included. Vesicles were characterized by determination of encapsulation efficiency and vanillin retention capacity. Antioxidant activity was determined by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) method. The hemolytic effect of liposomes was also evaluated by spectrophotometry, as well as the antisickling activity by the Huck test using optical microscopy. Results showed that the lipid composition of liposomes did not significantly affect the encapsulation efficiency. Stable vesicles were obtained with a high retention percentage of vanillin. Liposomes exhibited a high capture of the DPPH radical compared to free vanillin and 1-O-decylglycerol (C10) in solution. Vesicles caused no significant hemolisys in normal erythrocytes, nor in those coming from patients with sickle cell anemia. Vanillin encapsulated in liposomes retained its antisickling activity, with a greater effect for C10-containing vesicles. Our results show that vanillin encapsulation in liposomes is a way to enhance the pharmacologic properties of this molecule using a suitable vehicle.

Solenostemon monostachyus, Ipomoea involucrata and Carica papaya seed oil versus Glutathione, or Vernonia amygdalina: methanolic extracts of novel plants for the management of sickle cell anemia disease.

BACKGROUND: Sickle cell disease (SCD) is a genetic disease caused by an individual inheriting an allele for sickle cell hemoglobin from both parents and is associated with unusually large numbers of immature blood cells, containing many long, thin, crescent-shaped erythrocytes. It is a disease prevalent throughout many populations. The use of medicinal plants and nutrition in managing SCD is gaining increasing attention. METHODS: The antisickling effects of Solenostemon monostachyus (SolMon), Carica papaya seed oil (Cari-oil) and Ipomoea involucrata (Ipocrata) in male (HbSSM) and female (HbSSF) human sickle cell blood was examined in vitro and compared with controls, or cells treated with glutathione or an antisickling plant (Vernonia amygdalina; VerMyg). RESULTS: Levels of sickle blood cells were significantly reduced (P < 0.05) in all the plant-extract treated SCD patients' blood compared with that of untreated SCD patients. RBCs in SolMon, Ipocrata, and Cari-oil treated samples were significantly higher (P < 0.05) compared with VerMyg-treated samples. The Fe(2+)/Fe(3+) ratio was significantly reduced (P < 0.05) in all plant extract-treated HbSSM samples compared with controls. Hemoglobin concentration was significantly increased (P < 0.05) by SolMon treatment in HbSSF compared with VerMyg. Sickle cell polymerization inhibition exhibited by SolMon was significantly higher (P < 0.05) compared with that of VerMyg in HbSSF blood. Sickle cell polymerization inhibition in SolMon and Ipocrata were significantly higher (P < 0.05) compared with VerMyg in HbSSM blood. All plant extracts significantly reduced (P < 0.05) lactate dehydrogenase activity in both HbSSM and HbSSF-treated blood. Catalase activity was significantly increased (P < 0.05) in HbSSF blood treated with Ipocrata compared with glutathione. Cari-oil treated HbSSM and HbSSF blood had significantly increased (P < 0.05) peroxidase activity compared with controls. CONCLUSIONS: Methanolic extracts from S. monostachyus, C. papaya seed oil and I. involucrata exhibited particular antisickling properties coupled with the potential to reduce stress in sickle cell patients. Each plant individually or in combination may be useful for the management of sickle cell disease.

Advances in sickle cell disease treatment: from drug discovery until the patient monitoring.

Sickle cell disease (SCD) is one of the most prevalent hematological diseases in the world. Despite the immense progress in molecular knowledge about SCD in last years few therapeutical sources are currently available. Nowadays the treatment is performed mainly with drugs such as hydroxyurea or other fetal hemoglobin inducers and chelating agents. This review summarizes current knowledge about the treatment and the advancements in drug design in order to discover more effective and safe drugs. Patient monitoring methods in SCD are also discussed.

A novel high-throughput screening assay for sickle cell disease drug discovery.

Although the pathophysiology and molecular basis of sickle cell disease (SCD) were described more than half a century ago, an effective and safe therapy is not yet available. This may be explained by the lack of a suitable high-throughput technique that allows rapid screening of thousands of compounds for their antisickling effect. The authors have thus developed a novel high-throughput screening (HTS) assay based on detecting the ability of red blood cells (RBC) to traverse a column of tightly packed Sephacryl chromatography beads. When deoxygenated, sickle RBC are rigid and remain on the top of the column. However, when deoxygenated and treated with an effective antisickling agent, erythrocytes move through the Sephacryl media and produce a red dot on the bottom of the assay tubes. This approach has been adapted to wells in a 384-well microplate. Results can be obtained by optical scanning: The size of the red dot is proportional to the antisickling effect of the test molecule. The new assay is simple, inexpensive, reproducible, requires no special reagents, and should be readily adaptable to robotic HTS systems. It has the potential to identify novel drug candidates, allowing the development of new therapeutic options for individuals affected with SCD.

Preliminary in vitro antisickilng properties of crude juice extracts of Persia Americana, Citrus sinensis, Carica papaya and Ciklavit®.

The antisickling properties of crude juice extracts of the edible portions of three commonly consumed tropical fruits namely Persia americana, Citrus sinensis, and Carica papaya were investigated in vitro alongside a new drug preparation called Ciklavit® that has antisickling activity. Four different solvent extracts of the crude juice of each fruit including aqueous, acidic, alkaline and alcoholic extracts were prepared and their antisickling effects on sickle cell trait (HbAS) and sickle cell disease (HbSS) blood samples checked alongside Ciklavit®. Blood samples were stabilized using normal saline and the antisickling effects were checked by counting the number of sickle cells remaining after incubation of the blood samples with the crude fruit extracts and Ciklavit® for twenty-four hours. The results showed that Ciklavit® produced a sustained reduction in the number of sickle cells in both HbAS and HbSS blood samples. Also the alkaline and alcoholic extracts of P. americana and C. papaya produced significant reduction in the number of sickle cells.

Antisickling activity of anthocyanins from Bombax pentadrum, Ficus capensis and Ziziphus mucronata: photodegradation effect.

AIM OF THE STUDY: A survey was conducted in Lubumbashi city (Democratic Republic of Congo) in order to: (a) identify medicinal plants used by traditional healers in the management of sickle cell anaemia, (b) verify their antisickling activity in vitro, (c) determine the most active plants, and (d) verify if anthocyanins are responsible of the bioactivity and study their photodegradation effect. MATERIALS AND METHODS: The Emmel test was used in vitro, for the antisickling activity assays of aqueous and ethanolic extracts of different parts of these plants when a UV lamp and solar irradiations were used to induce the photodegradation effect. RESULTS: The survey revealed that 13 medicinal plants are used in the treatment of drepanocytosis among which 12 plants exhibited the in vitro antisickling activity for at least one of the used parts or extracts. These plants are Bombax pentadrum, Bougainvillea sp., Byarsocarpus orientalis, Dalberigia bochmintaub, Diplorrhynbchus condolocarpus, Euphorbia heterophylla, Ficus capensis, Harungana madagascariensis, Parinari mobola, Pothmania witfchidii, Syzygium guineense, Temnocalys verdickii and Ziziphus mucronata of which four (Bombax pentadrum, Ficus capensis, Parinari mobola and Ziziphus mucronata) revealed a high antisickling activity. The biological activity of three of these plants is due to anthocyanins. The antisickling activity and photodegradation effect of anthocyanins extracts were studied and minimal concentration of normalization determined. The biological activity of Bombax pentadrum anthocyanins decreased to half of its value after 40 min of irradiation under a lamp emitting at a wavelength of 365 nm and after about 10h of solar irradiation. For Ziziphus mucronata and Ficus capensis, the antisickling activity decreased to half after about 6h under a lamp exposition and after about 50h of solar exposition. CONCLUSION: In vitro Antisickling activity justifies the use of these plants by traditional healers and this activity would be due to anthocyanins. But these natural pigments are instable towards UV-Visible irradiations. The conservation of these plants should then be performed in a shield from the sun radiation.

[Effect of Morinda lucida Benth. (Rubiaceae) and Newbouldia leavis P. Beauv. (Bignoniaceae) on sickling of red blood cells]. / Effet de Morinda lucida Benth. (Rubiaceae) et de Newbouldia leavis P. Beauv. (Bignoniaceae) sur la falciformation.

The purpose of this study was to evaluate the In vitro anti-sickling activity of two plants widely used for treatment of sickle cell disease in Togo, i.e., Morinda lucida et Newbouldia leavis. A concentration-dependent decrease in the rate of sickling was observed after incubation of red blood cells with plant extracts and 2% sodium metabisulfite as compared to incubation with 0.9% NaCl. On samples with a SS blood genotype the inhibition rate of Morinda lucida was 17.30% at a concentration of 1 mg/ml and 92.31% at a concentration of 30 mg/ml. On samples with an AS blood genotype, the inhibition rate of Morinda lucida 48.10% at a concentration of 1 mg/ml and 99.34% at a concentration of 30 mg/ml. Using Newbouldia leavis the inhibition rates at concentrations of 1 mg/ml and 30 mg/ml were 15.66% and 90.42% respectively on samples with a SS blood genotype and 64.03% and 99.02% respectively on samples with an AS blood genotype. The study protocol appeared to be adequate for both SS and AS blood genotypes since the Pearson correlation coefficient between rates measured on the two types of samples was 0.92 for Newuboulida and 0.89 for Morinda. These findings show that these two plants have clear-cut in vitro anti-sickling activity and support their use in traditional medicine.

Pomalidomide and lenalidomide regulate erythropoiesis and fetal hemoglobin production in human CD34+ cells.

Sickle-cell disease (SCD) and beta thalassemia constitute worldwide public health problems. New therapies, including hydroxyurea, have attempted to augment the synthesis of fetal hemoglobin (HbF) and improve current treatment. Lenalidomide and pomalidomide are members of a class of immunomodulators used as anticancer agents. Because clinical trials have demonstrated that lenalidomide reduces or eliminates the need for transfusions in some patients with disrupted blood cell production, we investigated the effects of lenalidomide and pomalidomide on erythropoiesis and hemoglobin synthesis. We used an in vitro erythropoiesis model derived from human CD34+ progenitor cells from normal and SCD donors. We found that both compounds slowed erythroid maturation, increased proliferation of immature erythroid cells, and regulated hemoglobin transcription, resulting in potent induction of HbF without the cytotoxicity associated with other HbF inducers. When combined with hydroxyurea, pomalidomide and, to a lesser extent, lenalidomide were found to have synergistic effects on HbF upregulation. Our results elucidate what we believe to be a new mechanism of action of pomalidomide and lenalidomide and support the hypothesis that pomalidomide, used alone or in combination with hydroxyurea, may improve erythropoiesis and increase the ratio of fetal to adult hemoglobin. These findings support the evaluation of pomalidomide as an innovative new therapy for beta-hemoglobinopathies.

Phytochemical and antisickling studies of the leaves of Hymenocardia acida Tul (Euphorbiaceae).

The leaves of Hymenocardia acida are commonly used in Northern Nigeria alone or in combination with other plant parts to manage sickle cell disease. Phytochemical screening and antisickling studies were carried out. The phytochemical screening revealed the presence of carbohydrates, tannins, flavonoids, saponins, alkaloids, cardiac glycosides, resins, steroids and terpenes. The leaves ethanol extracts at 0.5, 1.0 and 2.0% w/v were observed to reverse sickled human Red Blood Cells (RBC) using microscopic technique. The antisickling activity was found to be dose dependent. The fractions containing flavonoids, saponins and carboxylic acids were found to be responsible for reversal of the sickled RBC. Therefore, the use of the plant by the traditional medical practitioners in the treatment of sickle cell anaemic patients is justified.

In vitro antidrepanocytary actvity (anti-sickle cell anemia) of some congolese plants.

Thirty aqueous and ethanolic extracts from 13 congolese plants were evaluated for their antidrepanocytary activity. Twelve of these plants, Alchornea cordifolia, Afromomum albo violaceum, Annona senegalensis, Cymbopogon densiflorus, Bridelia ferruginea, Ceiba pentandra, Morinda lucida, Hymenocardia acida, Coleus kilimandcharis, Dacryodes edulis, Caloncoba welwithsii, and Vinga unguiculata exhibited significant activities, thus, supporting the claims of the traditional healers and suggesting a possible correlation between the chemical composition of these plants and their uses in traditional medicine.

LC/MS/NMR analysis of isomeric divanilloylquinic acids from the root bark of Fagara zanthoxyloides Lam.

Gradient HPLC coupled to DAD/UV, MS/MS and NMR has been applied to the rapid structure determination of three new isomeric divanilloylquinic acids from Fagara zanthoxyloides collected in Burkina Faso: 3,4-O-divanilloylquinic acid, 3,5-O-divanilloylquinic acid and 4,5-O-divanilloylquinic acid. Furthermore these new compounds named burkinabins A-C could play a useful role in sickle cell disease, as the active agents of Fagara zanthoxyloïdes are said to be unidentified aromatic compounds with carboxylic acid grouping (Adesanya, S.A., Sofowora, A., 1983. Biological standardisation of Zanthoxylum roots for antisickling activity. Planta Med. 48, 27-33).

Anti-sickling potential of a Nigerian herbal formula (ajawaron HF) and the major plant component (Cissus populnea L. CPK).

The anti-sickling activities of the extracts of the roots of a plant Cissus populnea L. (CPK) (a major constituent of a herbal formula Ajawaron HF used in the management of sickle cell disease in south-west Nigeria) has been examined. Phytochemical examination of the extract showed the presence of anthraquinone derivatives, steroidal glycosides and cardiac glycosides. Alkaloids and tannins were completely absent in the CPK extracts. Evaluation of the anti-sickling activity involved the use of both positive (p-hydroxybenzoic acid, 5 microg/mL) and negative control (normal saline) for each set of experiments aimed at the inhibition of sodium metabisulphite-induced sickling of the HbSS red blood cells obtained from confirmed non-crisis state sickle-cell patients. The chloroform and water partitioned fractions of the cold methanol extracts of CPK exhibited a 62.2% and 52.9% inhibition of sickling, respectively, at 180 min. The herbal formula (HF) aqueous extract showed the highest anti-sickling activity on a weight by weight basis of all the extracts and fractions tested, giving a 71.4% inhibition of sickling at the end of 180 min incubation when compared with the normal saline control. The maximum percentage inhibition of sickling exhibited by the p-hydroxybenzoic acid control was 46.0% at 90 min incubation.

The kinetics of reversal of pre-sickled erythrocytes by the aqueous extract of Cajanus cajan seeds.

The aqueous methanol extract (3:1, v/v) of the seeds of Cajanus cajan was investigated for antisickling properties. The extract possessed significant antisickling activity and was found to be concentration-dependent. The kinetics of reversal of presickled erythrocyte (HbSS) cells using the extract at 0.5 mg/mL, 1.0 mg/mL, 1.5 mg/mL, 2.0 mg/mL and 2.5 mg/mL showed first-order kinetics with rate constants of 5.833 x 10(-3) min(-1), 6.143 x 10(-3) min(-1), 5.957 x 10(-3) min(-1) 6.00 x 10(-3) min(-1) and 6.046 x 10(-3) min(-1), respectively, and with an average half-life 115.6 min. Phytochemical screening of the extract revealed the presence of free amino acids, phenolic compounds, tannins, globulins and saponins. These results show that the extract has potential use in the management of painful episodes experienced by sickle cell patients.

In vitro effects of NIPRISAN (Nix-0699): a naturally occurring, potent antisickling agent.

Among the various potential antisickling agents tested, hydroxyurea (HU) has been the most effective compound used for the treatment of patients with sickle cell disease (SCD). Although HU is effective in many patients, not all patients respond to this drug. In addition, some patients reveal adverse effects, including myelosuppression. In an attempt to find other effective agents with less adverse effects, we investigated the antisickling effect of NIPRISAN (Nix-0699). We found that Nix-0699, an ethanol/water extract from indigenous plants, has a strong antisickling effect. The concentration of Nix-0699 required to inhibit 50% of erythrocyte sickling was about 0.05 mg/ml. As for the kinetics of polymerization, addition of 0.05 microg/ml Nix-0699 caused a sixfold prolongation of the delay time prior to deoxy-Hb S polymerization when compared with that of untreated Hb S samples. The solubility of deoxy-Hb S significantly increased upon treatment with Nix-0699. Analysis of the effect of Nix-0699 on the Hb S oxygen affinity indicated that the drug slightly shifted the oxygen-dissociation curve of Hb S toward the left without any apparent change in the Hill coefficient. These results suggest that the antisickling properties of Nix-0699 may involve direct interaction with Hb molecules. Incubation of red blood cell (RBC) suspensions with various concentrations of Nix-0699 did not dehydrate RBCs, cause haemolysis, increase the amount of denatured Hb, nor form met-Hb. In view of the outcome of this study, Nix-0699 may be a promising option for the treatment of patients with SCD.

Effect of niprisan on single oral dose pharmacokinetics of paracetamol in rats.

The single oral dose pharmacokinetics of paracetamol was studied alone and after coadministration with NIPRISAN In rats. Paracetamol concentrations were measured in rat plasma using UV-spectrophotometer and the data were fitted into an open two-compartment pharmacokinetic model using the computer program (STATIS Version 3.0). Results indicated no significant difference in the absorption of paracetamol between study and control groups but a significant reduction (p < 0.05) at some sampling time as the dose of NIPRISAN was increased double-fold. The pharmacokinetic parameters showed only 1.51 and 7.19% reduction in AUC(0-infinity) and Cmax respectively for paracetamol (20 mg/kg) + NIPRISAN (500 mg/kg). It was thus concluded that the gastric presence of NIPRISAN did not significantly reduce the absorption of paracetamol in rats.